Damper-operating mechanism for furnace doors



Mar. 13, 1923.

J. J.-A. MILLER ET AL DAMPER OPERATING MECHANISM FOR FURNACE DOORS I Filed Jan.

lNl/E/VTORS A TTOR/VE Y Patented Mar. 13, 1923.

JOHN J. A. MILLER AND WILLIAM A. WEIGELE, OF DENVER, COLORADO, essIGNoRs, BY DIRECT AND MESNE ASSIGNMENTS, TO THE AUTOMATIC FURNACE OXIDATOR AND MANUFACTURING COMPANY, or DENVER, COLORAD CORPORATION or COLORADO.

DAMEER-OPER-ATING MECHANISM FOR, FURNACE DOORS.

Application filed January 5, 1920. Serial No. 349,544.

To all whom. it may cmicern:

Be it known that we, JOHN J A. MILLER and \VILLIAM A. TVEICELE, citizens of the United States of America, residing at the city and county of Denver and State of Colorado, have invented a new and useful Damper-Operating Mechanism for l urnace Doors, of which the following is a specification.

Our invention relates to improvements in damper opening mechanism, and more particularly to mechanism of this character employed in operating the dampers of smoke abating mechanism of furnace doors, as set forth in a pending application, filed by us on December 15, 1919, Serial No. 344,859 for oil controlled furnace door attachments for effecting fuel combustion in furnaces, and which prior application discloses, in part, the subject matter of the present invention.

The object of the invention is to provide a furnace door-opening handle or lever and means operated thereby, for opening a damper in said door simultaneously with the opening of the door, or when the said lever is raised, whether the said door is opened or not opened.

Further, to provide, in connection with a furnace door having an air inlet pipe extending therethrough, a rod in said pipe having a damper thereon, and a tappet on one end of said rod, a door opening lever, and an arm pivotally connected thereto for engaging the tappet to open the damper when the lever is raised, and for swinging out of engagement with the tappet when the lever is lowered, to permit the said damper to be gradually closed by other mechanism.-

These objects are accomplished by the mechanism illustrated in the accompanying drawings, in which:

Figure 1 is a front elevation of a furnace door having" an air inlet pipe, a damper therein, and provided with the improved damper operating mechanism.

Fig. 2 is an enlarged side view of Figure 1. i

Fig. 8 is a plan view of Figure 2, partly in section.

Fig. 4 is a perspective view of the dooropening. lever. i

Fig. 5 is a fragmental sectional new showing a portion of the cylinder and the piston of an oil controlled gravity valve for closing the damper at a predetermined time after it is opened. And

Fig. 6 is a side view illustrating a slight modification in the closing means connecting the piston rod of the gravity valve and the damper rod. r

Referring to the accompanying drawings: The numeral 1, indicates a furnace door, and 2, an air inlet pipe which forms part of a ring-shaped member 3, of a bracket 4:.

which is secured to the furnace door, the

door being provided with an opening 5, through which is loosely passed a short section of threaded pipe 6, of the same diameter as the pipe 2, the pipe 6, being screwed into the ring 3.

One section 7, of a two-part air heating box, is provided with an aperture to receive the pipe 6, and this section is slipped over the pipe so as to rest against the rear side of the furnace door, and is secured inthis position by a clamping nut 8, which is screwed upon the pipe 6, and against the box section 7 thus securing the bracket 4:, to the front side of the door, and the box section 7, to the rear side of the door. Any further description of the air heating boX is deemed unnecessary, as it forms no part of the present invention.

The bracket 4, is provided withapertured ears 8, and witha horizontal projection or shelf 9, to which is secured an oil controlled gravity valve for effecting and controlling the closing of the damper, as will hereinafter appear. A transverse damper rod 10, extends through the pipe 2, and is provided with a damper 11. One endof the damper rod has a toothed segment 12 ,secured thereon, from which projects a stem-like tap-pet- 13, in the end of which is screwed a shouldered screw 14, and the shank of this screw, between its head and the end'of the tappet 13, lies in the bifurcated upper end of a vertically disposed arm 15, the lower end of which is pivotally attached to an inverted L- shaped lever 16, at the intersection of the horizontal and vertical members of said lever; the free end of the said horizontallv cured to said ears by a pin 17, which passes through the ears and through the end of the lever.

The lower end of the lever 16, terminates in a hand hold member 18, and the pivoted end of the lever is formed with oppositely disposed lugs 19, having threaded apertures,

in which are screwed stop bolts 20 and 21,

the latter bolt being adapted to abut against the bracket 4, to define the downward swing of the lever, while the bolt 20, defines the upward swing of the lever. This lever forms the door-opening lever, and by properly adjusting the stop bolts, the arm 15, is raised only far enough to fully open the damper, and lowered so far that when the tappet rests in the crotch 15 of the bifurcated end of the arm 15, the damper will be closed.

l/Vhen the stopbolt 20, strikes the bracket 4, a pull on the lever will result in opening the furnace door. From the foregoing, it will be seen that when the damper is closed, the tappet lies in the crotch of the forked end of the lever 15, and when the lever is swung upward, the arm 15, lifts until it rests in the crotch 15 the lever 15,

being swung thereby to accommodate the arc of travel of the said tappet. The damper is swung to a closed position by mechanism that is connected with the damper rod, and that will so retard the closing of the damper as to permit air to enter the combustion chamber of the furnace for a sufficient period after the ,coaling operation, to mingle with and cause thorough combustion of the floating particles of carbon and tar, by which visible smoke is eliminated. Various mechanism might be employed for gradually closing the damper, and the form of connection between the closing mechanism and damper would vary accordingly. In the present application, the form of connection is that of a rack and segment, and we have illustrated an oil controlled gravity valve as a means of gradually closing the damper through this rack and segment connection.

The oil valve comprises a cylinder 22, having upper and lower caps 23 and 24, respectively, which are secured upon the ends of the cylinder, the lower head having a projecting lug 25,which fits in a socket in the shelf 9, and is secured therein by a clamp bolt 26. l Vithin the cylinder is a piston 27, comprising a hollow cylindrical portion'having a bottom wall provided. with an axial hole 28, the upper end of the piston consisting simply of a central hub 29, which is integrally connected to the surrounding piston wall by spider arms 30. The hub 29, is provided with a central threaded hole 31, and the upper end of the hub is counterbored to receive the lower end of a hollow piston rod 32, the said end being secured in the counterbore by a pin 33. The upper end of the piston rod has secured thereon, a member 34, which is provided with rack teeth which mesh with the teeth of the segment 12, so that when the segment is raised in the manner before described, the piston rod is thereby lifted.

A stem 35, a portion of which above its lower end is threaded, is passed down through the member 34, and through the hollow piston rod, and its threaded portion is screwed into the threaded hole 31, in the piston hub, the lower end portion 35, of the stem extending through and beyond the hole 28, in the bottom of the piston. The end portion 35, is unthreaded and of slightly less diameter than the remainder of the stem, thereby forming a shoulder 36. This shoulder 36, forms a stop to limit the upward movement of a disk valve 37, which is slidably mounted on the smooth portion 35, of the stem, and is. normally held against the shoulder 36, by a spiral coil spring 38, which surrounds the said portion 35, and is held under tension by a pin 39, in the lower end of the stem. A thumb nut 40, is secured upon the upper end of the stem, by which the stem can be adjusted up and down in the threaded hole 31, soas to vary the position of the disk valve with respect to the aperture 28, in the bottom of the piston, thereby regulating the flow of oil through the piston on the downward movement thereof. As the piston is raised by the lifting of the lever 16, the oil above it passes through the aperture 28, in the bottom of the piston, and out over the circumferential edge of the disk valve, which is of less diameter than the piston, the valve being moved away from the bottom of the piston and against the pressure of the spring 38, by the pressure of the oil through the aperture 28. Immediately upon the swinging of the lever 16, to its normal position, the piston 2'? begins to drop by gravity, and the disk valve, under the combined pressure of the oil and the tension of the spring 38, is forced up against the shoulder 36, of the stem, by which the space between the disk and the bottom of the piston is defined, and the downward pressure on the oil, by the piston and its valve, forces the oil up between the disk and the bottom of the piston, through the aperture 28, and thus the piston is permitted slowly to descend, the time required for its descent to the bottom of the cylinder being determined by thespace between the disk and the bottom of the piston, the space being determined by ,the adjustmentof the stem 21 The segment 12, is provided with acounterbalancing portion 41, whereby the weight of the piston acts positivelyto lower the segment, as the counterbalance prevents the segment from moving; down by gravity, vand thereby exertinga downward push on the piston rod and piston, as would otherwise be the case. I

In Figure 6, is illustrated aslight modification of the rack and segment mechanism. In this arrangement, the curved edge, of the segment 12*, is untoothed, and a toothed segmental plate 42, is secured on one side of the segment, and extends beyond the curved edge thereof,.and a similar but untoothed segmental plate 48, is secured upon the opposite side of the segment. The segmental I plates 42 and i3, lie on opposite sides of a member 34", on the-upper end of the piston rod, and a toothed rack 44:, is, secured upon the side of the said member 34 and meshes with the teeth ofthe segmental plate 42. The pitch line of the teeth of this rack is parallel with. and in line with the axis of the piston rod, and both the axis of the piston rod and the pitch line of the rack teeth are the same distance fromthe axis of the segment 1%. The segments 42 and 43 steady the movement of the piston rod, and as the pitch line of the rack .coincideswith the axis of the piston rod, the segment exerts a direct lifting action on the piston rod, by which the said rod is moved in a true vertical line.

Having described our invention, what we claim as new and desire to secure by Lettersv Patent, is

1. In a device of the character described,

damper when the swinging means is lifted;

and gravity means raised by the lifting of the tappet, for gradually closing the said damper.

2. In a device of the'character described, the combination with a furnace door, a damper therein having a supporting rod, and a tappet on said rod, of a lever for opening the door, an arm pivotally connected to said lever and having a bifurcated end to engage the tappet and thereby open the damper when the lever is lifted. and gravity means raised by the lifting of the tappet for gradually closing the damper.

3. In a device of the character described, the combination with a furnace door, a damper therein having a supporting rod,

' and a member on said rod having a tappet and a member Qnsaid rod having a tappet thereon,,of a lever vpivotally connected to the door for opening the same, and means for defining the upper and lower swinging movements of said lever, an 'arm,pivoted at one end-to said lever, its opposite end being bifurcated, saidtappet normally resting in the crotch of said bifurcation andbeing lifted to open the damper when the said,

lever is lifted, anda gravity device having a member in engagement :with the member on the damper rod, for gradually closing the damper.

5. Ina device of the character described,

the combination with a furnace door, a

damper therein having a supporting rod, and ,a toothed segment on said rod having a tappet thereoin of alever pivoted to said doorfor opening the same, an arm pivotally secured at .one. end to said lever and having a bifurcated opposite end for engaging said tappet to lift thesame and open the damper when the lever is raised, and a gravity device having a rack member in mesh with the toothed segment for gradually closing said damper.

6. In a device of the character described, the combination with a furnace door, a damper therein having a supporting rod, a toothed segment on said rod having a tappet, of means for opening the damper, comprising a door-opening lever pivoted to said door. an arm pivoted at one end to said lever, having a bifurcated opposite end for engaging the tappet to open the damper when the lever is raised, adjustable stops on said lever for limiting its 'up and down swinging movements, a gravity device having a rack in engagement with the toothed segment for gradually closing the damper, and means for regulating the descent of said gravity device.

7. In a device of the character described, the combination with a furnace door, of an opening device therefor comprising a lever pivoted to said door, having oppositely disposed lugs, and adjustable stop bolts in said lugs to limit the up and down swinging movements of said lever, a vertically dis posed arm pivoted at one end to said lever and having a bifurcated upper end. a damper in said door having a supporting rod, a toothed segment on said rod having ata-ppet which rests in the crotch of the bifurcation when the damper is closed, and which is raised by the lifting of the lever to open the damper, and a gravity device having a rack in mesh with the toothed segment, for gradually closing the damper, said stop bolts defining the opening and closing swing of the damper.

S. In a device of the character described, the combination with a furnace door, of an opening; device therefor comprising aninverted L'shaped lever pivotally attached at its upper end to the door, oppositely disposed lugs on said upper end, having adjustable stop bolts therein for defining the up and down swing of said lever, an arm pivoted at its lower end to said lever at the junction of its horizontal and vertical portions, the upper end of said arm being bifurcated, a damper in said. door having a sup-porting rod, a toothed segment on said rod having a tappet which lies in the crotch of said bifurcation when the damper is closed, and which is lifted by the raising of the said lever to open said damper, and an adjustable drop gravity device having a rack in mesh with said toothed segment for gradually closing the damper.

9. In a device of the character described, the combination with a furnace door having a bracket thereon provided with a furnace air inlet pipe, and a damper in said pipe having a supporting rod provided with a toothed segment having a ta-ppet thereon,

amazes of a door-opening lever pivotally secured to the bracket, and adjustable stops on said lever for engaging the bracket to limit the up and down movements of the lever, an arm pivoted at one end to said lever and adapted to engage the tappet and open the damper when the lever is raised, and a gravity device secured to said bracket and having a rack in mesh with said toothed segment for gradually closing said damper.

10. The combination with a furnace door, a damper rod having a damper thereon in said door, a toothed segment on said rod and means for raising the same to open the damper, of means for gradually closing the damper within a given period, comprising an oil holding cylinder on said door, a piston therein having a passage therethrough, a rod extending from said piston having a toothed portion in mesh with said segment, whereby the raising of the segment effects the raising of the piston rod, a vertically adjustable stem beneath the piston and adapted to control the flow of oil through the said passage on the gravity stroke of the piston, either to retard or accelerate its movement.

In testimony whereof we aflix our signatures in presence of two witnesses.

JOHN J. A. MILLER. WILLIAM A. WEIGELE.

Vitnesses:

G. SARenN'r ELLIOTT, ELIZABETH SMITH. 

